High Quality Content by WIKIPEDIA articles! A mercy rule, also well known by the slightly less polite term slaughter rule (or, less commonly, knockout rule and skunk rule), brings a sports event to an early end when one team has a very large and presumably insurmountable lead over the other team. It is called the mercy rule because it spares the losing team the humiliation of suffering a more formal loss, and denies the winning team the satisfaction thereof, and prevents running up the score, a generally discouraged practice in which the opponent continues to score beyond the point when the game has become out of hand. The mercy rule is most common in games such as baseball or softball, where there is no game clock and play could theoretically continue forever, although it is also used in sports such as hockey and American football. It is very rare in competitive sports beyond the high school level.